A conventional treadmill generally includes a base which has two side rails and two posts are connected on the two side rails. A control panel and a handle are connected between the two posts. A frame has two sides and a running belt is reeved onto two ends of the frame. The user is running on the running belt and the data of speed, calorie consuming and the rate of slope can be displayed on the control panel. The frame has one end pivotably connected between the two side rails of the base so that the frame can be pivoted upright when not in use so as to reduce the space occupied. The frame of treadmills is so heavy that the user cannot fold or unfold the, treadmill easily. Therefore, a folding mechanism is needed, especially when the frame is folded at a large angle, the user has to support the frame and this is not an easy job for most of the users. Besides, when an electrical folding mechanism is chosen, some inherent shortcomings are involved which includes too many parts, high cost, and high maintenance fee is required.
The present invention intends to provide a folding mechanism which has less number of parts and is easily to fold or unfold the frame.